Hunting for the Dark Matter Wake Induced by the Large Magellanic Cloud

By N. Garavito-Camargo, G. Besla, C. Laporte, K. Johnston, F. G'omez, L. Watkins. Astrophysical Journal, 2019

138 citations recorded by the source corpus.

Satellite galaxies are predicted to generate gravitational density wakes as they orbit within the dark matter (DM) halos of their hosts, causing their orbits to decay over time. The recent infall of the Milky Way’s (MW) most massive satellite galaxy, the Large Magellanic Cloud (LMC), affords us the unique opportunity to study this process in action. In this work, we present high-resolution (mdm = 4 × 104M⊙) N-body simulations of the MW–LMC interaction over the past 2 Gyr. We quantify the impact of the LMC’s passage on the density and kinematics of the MW’s DM halo and the observability of these structures in the MW’s stellar halo. The LMC is found to generate a pronounced wake, which we decompose in Transient and Collective responses, in both the DM and stellar halos. The wake leads to overdensities and distinct kinematic patterns that should be observable with ongoing and future surveys. Specifically, the Collective response will result in redshifted radial velocities of stars in the north and blueshifts in the south, at distances >45 kpc. The Transient response traces the orbital path of the LMC through the halo (50–200 kpc), resulting in a stellar overdensity with a distinct, tangential kinematic pattern that persists to the present day. The detection of the MW’s halo response will constrain the infall mass of the LMC, its orbital trajectory, and the mass of the MW, and it may inform us about the nature of the DM particle itself.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/2a25c152dadf03af9046e7c4e7d26358e5b493d3

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

The milky way total mass profile as inferred from Gaia DR2 (2019, background): “…2012; Wang et al. 2012; Cautun et al. 2014a; Hellwing et al. 2016) while the radial mass profile plays a key role in determining the orbits of satellite galaxies and tidal streams (e.g. Barber et al. 2014; Monachesi et al. 2019a; Fritz et al. 2018; Cautun et al. 2019; Garavito-Camargo et al. 2019).”
The Spur and the Gap in GD-1: Dynamical Evidence for a Dark Substructure in the Milky Way Halo (2018, background): “To reaffirm that the GD-1 perturber is not a luminous satellite, future work should recalculate their relative distances in a more realistic gravitational potential that includes the LMC and Sagittarius (for example, as a time-dependent expansion of basis functions; Garavito-Camargo et al. 2019).”